Manley Vari-Mu: Tube Compressor Plugin by Universal Audio

Universal Audio positions the Vari-Mu as a way to add definition and fidelity to single tracks, stereo buses, or an entire mix. The developer says it applies gain reduction with warm harmonic content and aims to avoid audible compression artifacts.

Channel linking keeps both sides of a stereo signal adjusted together, which helps preserve a matched stereo image. When channels are unlinked, Mid/Side processing is available for independent control of the stereo image. Choose between Left/Right and Mid/Side operation depending on whether you are working on a mono-compatible source or a wide bus.

A High Pass Sidechain filter reduces low-end pumping, so you can compress material such as overheads while keeping punchy bottom end. The Dry/Wet Mix control gives you parallel compression without a separate send, and the Headroom control adjusts the processor's overall level for your playback system.

Universal Audio says the plugin is intended for single instruments such as bass or lead vocals, subgroups such as strings or horns, and especially the mix bus, where it is meant to unify a mix.